In a typical fueling station, fuel is delivered through a network of underground tanks, pipes, fittings, sumps and dispensers. Shear valves are often utilized in this network to automatically close the flow of fluids and gases in a supply pipe when that pipe is exposed to unusual forces. In addition, shear valves operate to maintain the overall integrity of their associated network by breaking or shearing off at a predetermined weak point downline of their closed position. Thus, shear valve installations reduce the magnitude of spills and leaks that would otherwise be associated with such unusual forces.
For example, if a vehicle were to run over a dispenser equipped with shear valves, one or more of the shear valves associated with that dispenser would operate to close the flow of fuel or vapors from their respective supply pipes to that dispenser. Moreover, the affected shear valves would also allow the dispenser to be "broken off" from the remainder of the fueling network, thereby preserving the network's overall integrity. However, to ensure that the shear valves will break or shear at their designed location in such loading conditions, they must be adequately and stably anchored.
Another potential problem associated with fueling stations is that fluids, such as gasoline, can leak or spill from the network, enter the soil surrounding the network, and pass into the ground water. To contain such leaks and spills originating from dispensers and their fittings, dispenser sumps are often installed below the dispensers. In addition to containing leaks and spills, these sumps also provide access to the underground pipes, fittings, machinery and the like.
Therefore, to preserve the integrity of a fueling network, and to reduce the impact of contaminations related to fuel leaks and spills, it is advantageous to use both shear valves and dispenser sumps in fueling networks. In this regard, it would be advantageous for manufacturers of dispenser sumps to provide sumps that can be used with various dispenser and shear valve configurations, including both new and retrofit construction applications. Increased compatibility would allow manufacturers to reduce the number of sump models produced, thereby providing cost savings to both the manufacturer and the end user.
To best effectuate the collection of any fuel leaks or spills associated with their operation, and to optimize their accessability, shear valves are mounted in the mouth of a sump. Sumps often include a structural frame surrounding the sump mouth that, in addition to providing structural integrity to the sump shell, also provides an anchor in the concrete to which shear valves may be attached. Typical shear valves, however, cannot be mounted directly to the sump frame as they require an assured cleared distance from the sump wall and other obstructions for proper and safe operation, and must be properly oriented with pipe entries of the respective dispenser. Therefore, sump stabilizer bars, also known as shear valve stabilizer bars, must be used to anchor typical shear valves to such frames.
To ensure a shear valve remains stable and properly anchored when placed under a load, the valve's respective stabilizer bar must be designed to withstand the resultant rotational forces that will be applied at the points of connection between the shear valve and the stabilizer bar. Likewise, the stabilizer bar must also withstand the resultant rotational forces applied to its connections with the sump frame. Moreover, in addition to being stable, a stabilizer bar should be compatible with dispensers that have pipe entries located off the center line.
Although adjustable stabilizer bars are known in the field, they are commonly bulky and expensive to manufacture as they often require welding, bolting, and/or a variety of components. In addition to being ill-suited for multiple shear valve applications because of their bulk, existing designs are also limited in how close to the sump walls the shear valves or other components can be mounted. In applications where the dispenser model has pipe entries located very close to the side or end walls of the dispenser and sump, this limitation of existing stabilizer bars can only be overcome through the installation of special fittings, such as product offsets, or through the use of a different sump model.
Conventional stabilizer bars are also limited in that they are often rigid and need shims to make up clearance space between the bar and the respective walls of the sump. In addition, conventional stabilizer bar designs often require that various sizes of the bar be manufactured for various sizes and types of sumps. Therefore, there is a need for a stable and adjustable shear valve stabilizer bar that overcomes the aforementioned problems.